title: Association of the Val66Met polymorphism of the BDNF gene with primary cranial-cervical dystonia patients from South-west China.
abstract: BACKGROUND
  The etiology of primary dystonia remains unclear. Recent genetic studies suggest that the Val66Met polymorphism of the BDNF gene is a genetic modifier in cranial-cervical dystonia in Caucasians. However, the finding is not consistent.
  
  
  METHODS
  A total of 193 patients with primary cranial-cervical dystonia from the Department of Neurology, West China Hospital of Sichuan University was included. From the same region, 216 healthy individuals were recruited as a control group. The Val66Met SNP was identified by polymerase chain reaction-restriction fragment length polymorphism.
  
  
  RESULTS
  In the present study, cervical dystonia (59.59%) was the most common type of primary cranial-cervical dystonia. No significant difference was found in the genotype and minor allele frequencies between all patients and controls, between cervical dystonia patients and controls, and between craniocervical dystonia patients and controls. However, significant differences were found in the genotype and minor allele frequencies of Val66Met SNP between blepharospasm (BSP) patients and controls (P=0.0080 and P=0.0042, respectively), and between BSP patients and patients with craniocervical derived from BSP (P=0.0010 and P=0.0002, respectively).
  
  
  CONCLUSIONS
  Minor allele "A" of BDNF Val66Met SNP may increase the risk for developing BSP and may be a protective factor for preventing BSP progressing to craniocervical dystonia. More association studies involving a larger number of participants are needed to confirm the present findings.
authors.affiliation: Department of Neurology, West China Hospital, Sichuan University, 610041 Chengdu, Sichuan, China.
authors.forename: Yongping
authors.initials: Y
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Ke
authors.initials: K
authors.lastname: Chen
authors.forename: Rui
authors.initials: R
authors.lastname: Huang
authors.forename: Bi
authors.initials: B
authors.lastname: Zhao
authors.forename: Bei
authors.initials: B
authors.lastname: Cao
authors.forename: Jeanmarc
authors.initials: J
authors.lastname: Burgunder
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Shang
mesh_terms: D000328:Adult; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D002681:China / Q000453:epidemiology; D004421:Dystonia / Q000151:congenital; D005260:Female; D056726:Genetic Association Studies / Q000379:methods; D006801:Humans; D008297:Male; D008715:Methionine / Q000235:genetics*; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D014103:Torticollis / Q000151:congenital* / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics; D014633:Valine / Q000235:genetics*; D055815:Young Adult
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C579455:BDNF protein, human; D008715:Methionine; D014633:Valine
keywords: BDNF gene; Primary dystonia; Vel66Met polymorphism